Seasonal and Interannual Variability of Suspended Sediment and Chl a On the South-Central Alaska Shelf

• Main Author: Cullen, Kerstin E
• Format: Text
• Language: unknown
• Published: DigitalCommons@UMaine 2014
• Subjects: Phytoplankton populations; Primary productivity (Biology); Stream measurements; Alaska; Gulf of Alaska; Copper River; Oceanography; Kodiak; Yakutat
• Online Access: https://digitalcommons.library.umaine.edu/etd/2083; https://digitalcommons.library.umaine.edu/context/etd/article/3117/viewcontent/CullenKE2014_OCR.pdf

Ten years of 1 km resolution NASA MODIS ocean color satellite data (2003-2012) covering the south-central Alaska Shelf (SCAS) from Kodiak Island to Yakutat Bay are used to quantify the temporal/spatial variability of total suspended matter (TSM) and chlorophyll. Satellite-based estimates of TSM are used to mask the most biased regions of satellite-estimated chlorophyll (>1 g m-3) in daily scenes. These are formed into monthly composites and used to view seasonal and interannual variability in TSM and chlorophyll and then are compared to local environmental metrics such as wind mixing, wind-driven cross-shelf Ekman transport, river discharge from the Copper River, coastal freshwater and cloud cover to examine links to forcing. TSM distributions are dominated by high concentrations entrained in the eastern portion of the Alaska Coastal Current (ACC) along the highly phytoplankton are light limited over the SCAS. Due to persistent cloud cover, however, we cannot rule out the possibility that our view of chl a interannual variability is biased by undersampling.